If $a + b + c = -9$ and $x + y = 8$, what is $-4a + 6x - 4c + 6y - 4b$ ?
Answer: $= -4a - 4b - 4c + 6x + 6y$ $= (-4) \cdot (a + b + c) + (6) \cdot (x + y)$ $= (-4) \cdot (-9) + (6) \cdot (8)$ $= 36 + 48$ $= 84$